Something

class MyInjectorSrc(gst.BaseSrc):    __gsttemplates__ = (        gst.PadTemplate("src",                        gst.PAD_SRC,                        gst.PAD_ALWAYS,                        gst.caps_new_any()),        )    def __init__(self, name, buffer):        self.__gobject_init__()        self.mybuffer = buffer        self.set_name(name)            def do_create(self, size, offset):        dummybuffer = self.get_pad("src").alloc_buffer(0,self.mybuffer.size,self.mybuffer.caps)        return gst.FLOW_OK, self.mybuffer      def do_get_caps(self):        print "MyInjectorSrc.do_get_caps() was called"        return self.mybuffer.caps        def do_check_get_range(self):        print "MyInjectorSrc.do_check_get_range() was called"        gobject.type_register(MyInjectorSrc)